Solar collector thermostat

Abstract

A solar energy collector having therein a solar energy-absorbing panel in thermally-conductive relation to fluid conduits through which fluid is urged by an electrically controlled pump, and a thermostat associated with the collector and arranged to detect panel temperature as unaffected by the temperature of the fluid and operable to control activation of the pump in response to variations in temperature of the unaffected panel.

What is claimed is: 
     
       1. In a solar radiation collector having a radiationabsorbing panel with predetermined absorbing characteristics and piping means in thermally conductive relation with the panel for conducting fluid to be heated by thermal conduction from the panel, the combination therewith of a thermostat device comprising a thermostat having a surface area which possesses the same thermal absorpiton characteristics as the panel unaffected by the temperature of the fluid in the piping means. 
     
     
       2. In the combination set forth in claim 1, said thermostat being positioned within an opening in said panel with said surface area disposed substantially coplanar with the adjacent surrounding surface of the panel. 
     
     
       3. In the combination as set forth in claim 2, said surface area being disposed in thermally nonconductive spaced relation to the panel. 
     
     
       4. In the combination set forth in claim 3, said thermostat being supported on the panel by attachment means having low thermal conductivity. 
     
     
       5. In the combination set forth in claim 4, said attachment means being a cement. 
     
     
       6. In the combination set forth in claim 4, said attachment means being a plastic disc. 
     
     
       7. In the combination set forth in claim 3, said thermostat including a housing and said surface area comprising a surface of said housing. 
     
     
       8. In the combination set forth in claim 3, said surface area comprising a plate carried upon one side of said housing. 
     
     
       9. In the combination set forth in claim 8, said plate being disposed in thermally nonconductive spaced relation in the panel and mounted within said opening by an overlying disc of material transparent to solar radiation, said disc being attached to said plate, being of a size to span the space between the plate and surrounding portion of the panel, and being attached in a marginal area to said panel. 
     
     
       10. In a solar radiation collecting system, a main solar radiation collector having a radiation-absorbing panel with predetermined absorbing characteristics and piping means in thermally conductive relation with the panel for conducting fluid to be heated by thermal conduction from the panel, the combination therewith of a thermostat device comprising a miniaturized collector comprising an enclosure having an open upper side, a glazing closing said open side of the enclosure, a radiation-absorbing panel located within the enclosure beneath the glazing and having thermal absorption characteristics the same as those of the panel in the main collector unaffected by the temperature of the fluid in the piping means thereof. 
     
     
       11. In a system as set forth in claim 10, said miniaturized collector being mounted on one side of the main collector. 
     
     
       12. A system for heating water by solar radiation comprising at least one collector comprising an enclosure having an open upper side, a glazing on said open side of the enclosure, a radiation-absorbing panel positioned within the enclosure beneath the glazing and having predetermined radiation absorbing characteristics, piping means in thermally conductive relation with the panel for conducting fluid to be heated by thermal conduction from the panel, a storage tank containing fluid to be heated, a feed pipe connecting said tank to one end of said piping means, pump means for forcing fluid from the tank through the feed pipe and piping means, and a thermostat device operatively electrically connected to said pump means and including a surface area which possesses the same thermal absorption characteristics as said panel unaffected by the temperature of the fluid in the piping means and operable to turn on the pump means when the temperature of said surface area indicates a predetermined level of heat is available.